1. Field of the Invention
The present invention relates to thermoplastic compound flooring material. In particular, the present invention is a new UPVC/wood compound flooring material and manufacturing method thereof. The process represents a marked improvement in the manufacturing of compound flooring and the present invention is in many ways superior to previous generations of wood flooring.
2. Related Art
The compound floor (flooring material comprising multiple bonded layers of similar or dissimilar materials) has gained widespread acceptance in recent years. There are three basic methods for producing compound floor:
MOLDED FIBRE COMPOSITE COMPOUND FLOOR: Adhesives and additives are blended with wood pulp, then passed through high temperature, high pressure processing to become a solid molded product. This method of manufacturing overcomes the inherent instability of wood by elimination of the grain structure. However, the most commonly used adhesive in this process is formaldehyde, which is difficult to control, and often exceeds established limits in processing. This results in the continued emission of an irritating, and potentially hazardous odor after installation.
SOLID WOOD COMPOUND FLOOR: This method combines staggered layers of solid wood, with the top layer generally being a high quality hardwood, while sub-layers are of lesser quality. Some brands arrange center layers perpendicular to top and bottom layers (plywood technology) to form a more dimensionally stable product, while maintaining the look and feel of traditional solid wood flooring. This product has three general forms:
1) Three layered solid wood compound flooring;
2) Multi-layered solid wood compound flooring; and
3) New type solid wood compounding flooring.
PLASTIC SOLID WOOD COMPOUND FLOOR: This method is a new technology that combines three dissimilar layers to form a flooring material, e.g. as described in Chinese patent application 02210626.X. The top layer is usually a thin panel of high quality wood of various species. The central layer is foamed plastic shock absorbing layer, and the bottom layer is a filled PVC floor. In this type of PVC, sometimes a heavy metal like lead is used as a process aid. In such circumstances, the flooring could create a potentially hazardous product, which would be illegal in many countries.